81602260417 has 2 divisors, whose sum is σ = 81602260418. Its totient is φ = 81602260416.

The previous prime is 81602260393. The next prime is 81602260433. The reversal of 81602260417 is 71406220618.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41397599296 + 40204661121 = 203464^2 + 200511^2 .

It is a cyclic number.

It is not a de Polignac number, because 81602260417 - 2³¹ = 79454776769 is a prime.

It is not a weakly prime, because it can be changed into another prime (81602260457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40801130208 + 40801130209.

It is an arithmetic number, because the mean of its divisors is an integer number (40801130209).

Almost surely, 2^81602260417 is an apocalyptic number.

It is an amenable number.

81602260417 is a deficient number, since it is larger than the sum of its proper divisors (1).

81602260417 is an equidigital number, since it uses as much as digits as its factorization.

81602260417 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32256, while the sum is 37.

The spelling of 81602260417 in words is "eighty-one billion, six hundred two million, two hundred sixty thousand, four hundred seventeen".